We just realised that through an unfortunate series of events, I had removed a line that Arnaud had added in the documentation on the videoconference installation process. It was missing the part where you download the dokeos-conference.war file and copy it to your webapps directory. The audiorecording is there, but not the videoconference.
In any case, the documentation on our website is correct (except one occurence of the name of the file but that's obvious) and we have updated our code sources:
http://www.dokeos.com/doc/installation_guide.html
Sorry about that...